The present invention provides a method and apparatus for sampling and analyzing hazardous materials proximate the site and such that a an absolute minimum of hazardous material need be released or removed from the site.
According to one aspect of the invention, a remotely controlled mobile cart positions a probe proximate to the sampling site. A high energy wavelength laser ablates the material, forming a cloud of micron-sized particles. The particles are drawn from the sampling site by an aerosol system which employs an inert gas, such as argon. The sample particles and argon gas aerosol are injected into an inductively coupled plasma (ICP) source, which produces electromagnetic radiation which can be analyzed with an optical spectrometer.
In one embodiment, the laser source is located in a van or truck remote from the cart, with the laser beam from the source carried to the probe over an optical fiber. The inductively coupled plasma source is located on the mobile cart, with its optical output being carried over another optical fiber to an optical spectrometer located in the van or truck, from which the material analysis is obtained. In another embodiment, the laser and spectrometer are located on the cart.
The present invention also employs several unique probe structures which isolate the sampling site from the outside environment, ensuring that only the material ablated by the laser radiation is carried to the inductively couple plasma system (ICP) through the aerosol transport system. A special ceramic probe tip is employed to extract samples from molten materials.
Because length over which the aerosol system can carry the ablated sample, another embodiment collects the ablated sample on a filter media, which is taken to a remote site for analysis using the inductively coupled plasma system discussed above.
Finally, an ultrasonic or direct injection nebulization technique is used instead of the laser to produce aerosol particles from liquid materials at the sampling site to be analyzed by the ICP.